>>56280459A fucking what.
I'd like to think I've dropped enough lore in these threads to establish that most of my time in public is spent getting women to leave me alone, I'm sorry I don't have any firsthand experience spiking anyone's drinks or being spiked.
Are you asking how it happens? Typically a barbiturate solution is dropped into an unattended drink when no one's looking. This is why you don't leave drinks on the counter or accept freebies. Bartenders are taught to be on the lookout for that behavior (hovering over the table with their hands over their drink, sleight of hand tricks, intentionally talking quietly in a loud room so you lean in, the guilty dindu eyes whenever an authority figure comes around), but depending on how busy the bar is, they can't keep tabs on everything. If the bartender is a friend of the perpetrator, they might even be the one lacing it on their behalf. Mixing a pharmaceutical downer with a strong depressant like alcohol is a solid one-two punch against someone with a low body weight, especially if they continue partying or were already near their limit before the drugs kick in. They can also be mixed in with recreational drugs which is much harder to track and uncomfortable to report because the victim thinks they'll be tattling on themselves if they say anything (not the case, as the law is written). You could also get pricked with a syringe in a crowd, too.
Are you asking what compounds are used? Typically whatever prescription-grade horse tranquilizer is floating around the aftermarket since every normalfag and their dog is being forcefed anti-anxiety meds. Street dealers will make homebrewed potions too for their clientele, they're not exactly righteous people.
Are you asking how effective these are? Look up David Ray Parker's audio logs if you have a strong stomach. It works.